This invention relates to a portable apparatus for surface treatment by sandblasting in order to remove dirt, loose particles of the surface and rust. More particularly, it relates to a portable surface treating apparatus provided with an improved means of positioning and oscillating at least one nozzle so as to treat a pre-set width of surface. More particularly such surface treatment is effective for cleaning vehicular surfaces such as highway, airport runway or bridge deck surfaces when these are newly made, when these have been traveled and after broken and crumbling portions have been removed by air hammers or chisels or other means, so as to promote good bonding of coating, patching or overlaid material.
In U.S. Pat. No. 1,889,132, description is made of a multiple blast nozzle which could be used for cleaning a swath of surface if mounted on a movable platform.
The array of nozzles of the above referenced patent is restricted to the blast pattern produced by the array and may not be adjusted as to width. This is not satisfactory where it is desirable to clean various widths of surface such as roadway or highway lanes.
In U.S. Pat. No. 4,126,970, description is made of an abrasive cleaning apparatus with a nozzle holder which moves a plurality of nozzles as a unit. This array does not automatically oscillate but is under operator control. It is necessary to provide an operator which is a distinct disadvantage in terms of cost of operation and the work environment proximate to the sandblasting operation.
Accordingly, it is an object of the present invention to provide a mobile surface treating apparatus capable of complete and even coverage of a swath of road surface.
It is another object of the invention to provide a mobile surface treating apparatus capable of being adjusted quickly and easily to a given width.
It is still another object of the invention to provide a mobile surface treating apparatus capable of being adjusted over a great range of widths of surface to be treated in one swath.
It is yet another object of the present invention to provide a mobile surface treating apparatus capable of starting a swath from a wall, obstacle or other point with a beginning perpendicular to the direction of travel and all the way to said wall, obstacle or other point so as to eliminate or lessen the need for handwork.
It is a further object of the present invention to provide a mobile surface treating apparatus capable of reciprocating nozzles in gang fashion about pivot points which may be moved when setting up so as to vary the width of swept surface easily and accurately.
It is a yet further object of the present invention to provide a mobile surface treating apparatus capable of reciprocating nozzles in gang fashion by extendible means and upon pivot points upon an extendible support member so as to permit the ganging of additional nozzles so as to allow adjustment of width of treated surface to a greater width than possible without the addition of said additional nozzles.
It is still a further object of the invention to provide a mobile surface treating apparatus capable of operator control so as to turn off individual nozzles to permit operation with fewer nozzles or one nozzle so the width of treated surface is diminished to a desired narrow width without any change to the nozzle array, movable platform, or reciprocating means.
Other U.S. Pat. Nos. considered during the preparation of this application, but not believed pertinent to the present invention, are: 3,110,234 Oster, 3,432,969 Byttebier, 3,691,689 Goff, 3,934,373 Leliaert, 3,977,128 Goff, 4,019,284 Hileman.